The science and economics of drug discovery has changed with developments in the areas of genomics, combinatorial chemistry and high-throughput screening. The number of targets has increased as a result of genomics while the number of small molecule compounds (samples) has dramatically increased as a result of combinatorial chemistry. This increase in targets and compounds has an exponential effect on the number of tests that need to be performed to increase the likelihood of finding a new chemical entity using high-throughput screening. Microliter amounts of target and sample must suffice for many screening assays, putting pressure on the automation industry to provide new tools to accurately meter, mix and dispense liquids in doses as low as on the order of 10 nanoliters in many instances. Conventional R&D screening efforts use multiple variations of pipetting to move aliquots of the concentrated liquid sample from storage receptacles, to working receptacles, to dilution receptacles where the sample is diluted with a solvent such as pure dimethylsulfoxide (DMSO), and finally to assay receptacles. This “reformatting” process, or “sample preparation” can waste valuable sample or target and increase time and assay cost. Devices and methods are needed for accurately and efficiently handling these valuable liquids in such minute quantities, to increase screening productivity and accuracy.